Kegler Hauke F, Hassenrück Christiane, Kegler Pia, Jennerjahn Tim C, Lukman Muhammad, Jompa Jamaluddin, Gärdes Astrid
Department of Biogeochemistry and Geology, Leibniz-Centre for Tropical Marine Research, Bremen, Germany.
Faculty of Biology and Chemistry (FB2), University of Bremen, Bremen, Germany.
PeerJ. 2018 May 7;6:e4555. doi: 10.7717/peerj.4555. eCollection 2018.
Water quality deterioration caused by an enrichment in inorganic and organic matter due to anthropogenic inputs is one of the major local threats to coral reefs in Indonesia. However, even though bacteria are important mediators in coral reef ecosystems, little is known about the response of individual taxa and whole bacterial communities to these anthropogenic inputs. The present study is the first to investigate how bacterial community composition responds to small-scale changes in water quality in several coral reef habitats of the Spermonde Archipelago including the water column, particles, and back-reef sediments, on a densely populated and an uninhabited island. The main aims were to elucidate if (a) water quality indicators and organic matter concentrations differ between the uninhabited and the densely populated island of the archipelago, and (b) if there are differences in bacterial community composition in back-reef sediments and in the water column, which are associated with differences in water quality. Several key water quality parameters, such as inorganic nitrate and phosphate, chlorophyll , and transparent exopolymer particles (TEP) were significantly higher at the inhabited than at the uninhabited island. Bacterial communities in sediments and particle-attached communities were significantly different between the two islands with bacterial taxa commonly associated with nutrient and organic matter-rich conditions occurring in higher proportions at the inhabited island. Within the individual reef habitats, variations in bacterial community composition between the islands were associated with differences in water quality. We also observed that copiotrophic, opportunistic bacterial taxa were enriched at the inhabited island with its higher chlorophyll , dissolved organic carbon and TEP concentrations. Given the increasing strain on tropical coastal ecosystems, this study suggests that effluents from densely populated islands lacking sewage treatment can alter bacterial communities that may be important for coral reef ecosystem function.
由于人为输入导致无机和有机物质富集而引起的水质恶化，是印度尼西亚珊瑚礁面临的主要局部威胁之一。然而，尽管细菌是珊瑚礁生态系统中的重要介质，但对于单个分类群和整个细菌群落对这些人为输入的反应却知之甚少。本研究首次调查了在斯珀蒙德群岛几个珊瑚礁栖息地（包括水柱、颗粒物和礁后沉积物）中，细菌群落组成如何响应水质的小规模变化，这些栖息地分别位于一个人口密集的岛屿和一个无人居住的岛屿上。主要目的是阐明：（a）该群岛无人居住的岛屿和人口密集的岛屿之间水质指标和有机物浓度是否存在差异；（b）礁后沉积物和水柱中的细菌群落组成是否存在差异，以及这些差异是否与水质差异相关。几个关键的水质参数，如无机硝酸盐和磷酸盐、叶绿素以及透明胞外聚合物颗粒（TEP），在有人居住的岛屿上显著高于无人居住的岛屿。两个岛屿的沉积物和附着在颗粒物上的细菌群落存在显著差异，与营养物质和富含有机物条件相关的细菌分类群在有人居住的岛屿上所占比例更高。在各个珊瑚礁栖息地内，岛屿之间细菌群落组成的变化与水质差异相关。我们还观察到，在叶绿素、溶解有机碳和TEP浓度较高的有人居住的岛屿上，富营养型、机会主义细菌分类群有所富集。鉴于热带沿海生态系统面临的压力不断增加，本研究表明，缺乏污水处理的人口密集岛屿排放的废水会改变细菌群落，而这些细菌群落可能对珊瑚礁生态系统功能很重要。
